A sealed package containing a pourable food product and a sheet packaging material for producing a sealed package containing a pourable food product

ABSTRACT

A sealed package containing a pourable food product and comprising a bottom portion, a top portion and a main portion interposed between the bottom portion and top portion and including a plurality of side wall portions; the main portion is divided from the bottom portion and said top portion respectively by a bottom peripheral outline and a top peripheral outline extending transversally with respect to a longitudinal direction; each of the bottom peripheral outline and the top peripheral outline has a broken-line shape and is formed by a plurality of contour edges joined to each other; the bottom portion comprises a quadrilateral bottom panel delimited by the bottom peripheral outline and extending orthogonal to the longitudinal direction; the top portion comprises a quadrilateral top panel delimited by the top peripheral outline and extending transversally to the longitudinal direction; the area of the bottom panel is different from the area of a top quadrilateral obtained by projecting, along the longitudinal direction, the top panel on a reference plane parallel to the bottom panel, crossing the package and containing at least one of the contour edges of the top peripheral outline.

The present invention relates to a sealed package containing a pourablefood product.

The present invention also relates to a sheet packaging material forproducing a sealed package containing a pourable food product.

As commonly known, many pourable food products, such as fruit juice, UHT(ultra-high-temperature treated) milk, wine, tomato sauce, etc., aresold in packages made of sterilized packaging material.

A typical example is the parallelepiped-shaped package for liquid orpourable food products known as Tetra Brik Aseptic (registeredtrademark), which is made by folding, sealing and cutting a web oflaminated packaging material. In particular, the packaging material hasa multilayer structure comprising a base layer, e.g. of paper, coveredon both sides with layers of heat-seal plastic material, e.g.polyethylene. In the case of aseptic packages for long-storage products,such as UHT milk, the packaging material also comprises a layer ofoxygen-barrier material, e.g. an aluminium foil, which is superimposedon a layer of heat-seal plastic material, and is in turn covered withanother layer of heat-seal plastic material forming the inner face ofthe package eventually contacting the food product.

Packages of this sort are normally produced on fully automatic packagingmachines, on which a continuous tube is formed from the web-fedpackaging material; the web of packaging material is sterilized on thepackaging machine, e.g. by applying a chemical sterilizing agent, suchas a hydrogen peroxide solution, which, once sterilization is completed,is removed from the surfaces of the packaging material, e.g. evaporatedby heating; the web so sterilized is then maintained in a closed,sterile environment, and is folded and sealed longitudinally to form atube, which is fed vertically.

In order to complete the forming operations, the tube is filled with thesterilized or sterile-processed food product, and is sealed andsubsequently cut along equally spaced cross sections; pillow packs areso obtained, which are then folded mechanically to form respectivefinished packages at a final folder.

To allow folding of the web packaging material both during forming andfinal folding, crease lines, i.e. weakening lines, are formed on thepackaging material at the production plant by creasing tools. Inpractice, the crease lines define folding lines along which the pillowpacks are folded to take the desired final configuration.

Alternatively, the packaging material may be cut into blanks, which areformed into packages on forming spindles, and the resulting packages arethen filled with the food product and sealed. One example of this typeof package is the so-called “gable-top” package known by the trade nameTetra Rex (registered trademark).

To open the above-described packages, these are normally provided with aremovable portion, which is partly detached by an opening device fromthe rest of the packaging material to free a pour opening through whichto pour out the product.

The removable portion is formed on the packaging material prior tofolding and sealing the packaging material to form the finished package.

The removable portion normally comprises a so-called “prelaminated”hole, i.e. a circular hole formed through the base layer only of thepackaging material and covered, when the material is laminated, with thelayers of heat-seal plastic material and barrier material, which adhereto one another at the hole.

Each package of the above type, either cut from a tube of packagingmaterial or formed on a forming spindle, is obtained from a basic unitof packaging material having given crease lines.

In other words, the above-mentioned basic unit represents the exactlength of the packaging material used to produce one single package.

In the case of packages made from a tube of packaging material, theoriginal web includes a plurality of basic units joined to each other;in the case of packages made on forming spindles, the basic unit isdefined by the blank cut from the web prior to starting the forming andsealing operations.

The basic unit typically has a rectangular or square configuration withtwo boundary edges parallel to a longitudinal direction and two otherboundary edges parallel to a transversal direction orthogonal to thelongitudinal direction.

Once the basic unit is folded and sealed to form the respective finishedpackage, the longitudinal direction becomes the direction along whichthe total height of the package itself is defined; the longitudinaldirection also represents the main direction of extension of the webfrom which the basic unit is obtained.

The basic unit usually includes at least two transversal crease linesextending transversally to the longitudinal direction and dividing thebasic unit itself into:

-   -   a bottom region containing a bottom crease pattern and        configured to form a bottom portion of the finished package;    -   a top region containing a top crease pattern and configured to        form a top portion of the finished package; and    -   an intermediate region contained between the transversal crease        lines, interposed between the bottom region and the top region        and usually having a plurality of longitudinal crease lines        designed to form lateral edges of a plurality of side walls of        the finished package.

The transversal crease lines are also configured to define a bottomperipheral outline and a top peripheral outline of the finished packagehaving endless configurations and respectively dividing the bottomportion and the top portion from the main portion.

The bottom portion of the finished package normally includes a flat andhorizontal bottom panel defining the resting surface of the packageitself.

The top portion of the finished package may include a flat andhorizontal top panel, parallel to the bottom panel; alternatively,slanted top panels are very conveniently used in combination withopening devices because they are wider than corresponding flat toppanels of parallelepiped or prismatic packages and therefore allow theapplication of larger opening devices, e.g. provided with screw caps orthe like.

As it is known, after their production, packages are transported to salepoints by placing them on transport pallets, which have pre-determinedsizes. A need is therefore particularly felt in the packaging field tooptimize filling of the transport pallets with the finished packageswhile maintaining a pleasing appearance of such packages.

It is therefore an object of the present invention to provide a sealedpackage containing a pourable food produce, which allows meeting theabove-mentioned need in a straightforward and low-cost manner.

This object is achieved by a sealed package as claimed in claim 1.

This object is also achieved by a sheet packaging material for producinga sealed package containing a pourable food product, as claimed in claim13.

Four preferred, non-limiting embodiments of the present invention willbe described by way of example with reference to the accompanyingdrawings, in which:

FIG. 1 is a perspective view of a sealed package according to thepresent invention;

FIG. 2 is a smaller-scale front view of the package of FIG. 1;

FIG. 3 is a smaller-scale side view of the package of FIG. 1;

FIG. 4 is a smaller-scale bottom view of the package of FIG. 1;

FIG. 5 is the projection, along a vertical direction, of a top panel ofthe package of FIG. 3 on a horizontal plane containing a top front edgeof the top panel itself;

FIG. 6 is a front view of a basic unit of a sheet packaging materialaccording to the present invention, from which the package of FIGS. 1 to5 is obtained;

FIG. 7 is a perspective view of a sealed package according to adifferent embodiment of the present invention;

FIG. 8 is a front view of a basic unit of a sheet packaging materialaccording to the present invention, from which the package of FIG. 7 isobtained;

FIG. 9 is a perspective view of a sealed package according to anotherembodiment of the present invention;

FIG. 10 is a front view of a basic unit of a sheet packaging materialaccording to the present invention, from which the package of FIG. 9 isobtained;

FIG. 11 is a perspective view of a sealed package according to a furtherembodiment of the present invention; and

FIG. 12 is a front view of a basic unit of a sheet packaging materialaccording to the present invention, from which the package of FIG. 11 isobtained.

Number 1 in FIGS. 1 to 5 indicates as a whole a sealed package accordingto the present invention, which contains a pourable food product and isobtained from a sheet packaging material 2 as shown in FIG. 6.

Package 1 comprises a bottom portion 3, a top portion 4 and a mainportion 5 interposed between bottom portion 3 and top portion 4 andincluding a plurality of side wall portions 6, each one delimited by twoopposite lateral edge zones 7.

Main portion 5 is divided from bottom portion 3 by a bottom peripheraloutline 8 having an endless configuration defined by a broken line. In acompletely analogous manner, main portion 5 is divided from top portion4 by a top peripheral outline 9, also having an endless configurationdefined by a broken line.

Bottom portion 3 includes a flat and horizontal bottom panel 10 having aquadrilateral, i.e. rectangular or square (in the example shownrectangular), profile and defining the resting surface of the packageitself.

Bottom panel 10 is delimited by bottom peripheral outline 8 in turnformed by four segments or contour edges, i.e. a bottom front edge 8 a,a bottom rear edge 8 b parallel to bottom front edge 8 a and two bottomside edges 8 c, orthogonal to bottom front edge 8 a and bottom rear edge8 b.

Due to the rectangular profile of bottom panel 10, bottom front edge 8 aand bottom rear edge 8 b have the same length; the same applies tobottom side edges 8 c, which also have the same length.

Package 1 extends vertically along a longitudinal direction A, which isorthogonal to bottom panel 10 and along which the total height of thepackage 1 itself is defined. Longitudinal direction A is also orthogonalto bottom front edge 8 a, bottom rear edge 8 b and bottom side edges 8 cof bottom peripheral outline 8.

It is pointed out that, in the present description and in the claims,the term “total height” means either the height of the package when thelatter has a constant height or the maximum height of the package whenthe latter has a variable height.

Bottom portion 3 further includes two bottom lateral flaps 11 havingsubstantially triangular configurations and folded in a known manneronto bottom panel 10 (FIG. 4).

Top portion 4 includes a flat and slanted top panel having aquadrilateral, i.e. a square or a rectangular, profile and having asloping configuration forwards with respect to longitudinal direction A.

In the example shown in FIGS. 1 to 3, top panel 14 is a rectangleapproximating a square.

Top panel 14 is delimited by top peripheral outline 9 in turn formed byfour segments or contour edges, i.e. a top front edge 9 a parallel tobottom front edge 8 a and bottom rear edge 8 b, a top rear edge 9 b,parallel to top front edge 9 a and arranged higher than the top frontedge 9 a itself, and two top side edges 9 c, orthogonal to top frontedge 9 a and top rear edge 9 b and inclined with respect to longitudinaldirection A.

As a consequence, top peripheral outline 9 extends transversally withrespect to longitudinal direction A.

Due to the rectangular profile of top panel 14, top front edge 9 a andtop rear edge 9 b have the same length; the same applies to top sideedges 9 c, which also have the same length.

Top portion 4 further includes two top lateral flaps 15 havingsubstantially triangular configurations and folded in a known manneronto two opposite side wall portions 6 of main portion 5.

As visible in FIGS. 1 to 3 and 5, top portion 4 is also provided with anopening device 16 of plastic material placed over and around a removableportion 17 (FIG. 6) of the packaging material 2. Opening device isapplied onto top panel 14 by conventional fastening systems, such asadhesives, or by micro-flame, electric-current-induction, ultrasound,laser, injection moulding or other heat-sealing techniques.

In the example shown in FIGS. 1 to 5, main portion 5 of package 1includes four side wall portions with different profiles and sizes;advantageously, lateral edge zones 7 delimiting side wall portions 6have rounded configurations.

In particular, a first side wall portion 6, designed to define a frontface of package 1, has a substantially rectangular configurationdelimited, at bottom and top, by straight bottom front edge 8 a and topfront edge 9 a, and at opposite sides, by respective rounded and convexlateral edge zones 7.

A second side wall portion 6, designed to define a rear face of package1, also has a substantially rectangular configuration and is delimited,at bottom and top, by straight bottom rear edge 8 b and top rear edge 9b, and at opposite sides, by respective rounded and convex lateral edgezones 7; this second side wall portion 6 faces the side wall portion 6designed to define the front face of the package 1 and has a height,parallel to longitudinal direction A, greater than the height of thislatter side wall portion 6.

Each of the other two side wall portions 6 has a profile substantiallyresembling a rectangular trapezium delimited:

-   -   at the bottom, by one respective horizontal bottom side edge 8        c;    -   at the top, by one respective inclined top side edge 9 c; and    -   at opposite sides, by respective rounded and convex lateral edge        zones 7.

The two side wall portions 6 having the trapezoidal profiles receive therespective top lateral flaps 15 on their outer surfaces.

According to an important aspect of the present invention, the area ofbottom panel 10 is different from the area of a top quadrilateral Q(FIG. 5) obtained by projecting, along longitudinal direction A, toppanel 14 on a reference plane P (FIG. 3) parallel to the bottom panel10, crossing package 1 and containing top front edge 9 a of topperipheral outline 9.

In particular, the area of bottom panel 10 is smaller than the area oftop quadrilateral Q.

According to another possible variant not shown, the area of bottompanel 10 may be bigger than the area of top quadrilateral Q.

Analogously to top panel 14, top quadrilateral Q is a square or arectangle, in the examples shown a rectangle approximating a square.

With particular reference to FIG. 5, top quadrilateral Q includes a topfront segment Q1, corresponding to bottom front edge 8 a, a top rearsegment Q2, corresponding to bottom rear edge 8 b, and two top sidesegments Q3, respectively corresponding to bottom side edges 8 c.

Preferably, top side segments Q3 have the same length, which is in turndifferent from the length of bottom side edges 9 c. More specifically,in the example shown, the length of bottom side edges 9 c is smallerthan the length of top side segments Q3.

In a similar way, top front segment Q1 and top rear segment Q2 have thesame length, which is in turn different from the length of bottom frontedge 8 a and bottom rear edge 8 b.

More specifically, in the example shown, the length of bottom front edge8 a and bottom rear edge 8 b is greater than the length of top frontsegment Q1 and top rear segment Q2.

The packaging material 2 from which package 1 is made is shown in FIG. 6and has a known multilayer structure (not shown) comprising a baselayer, e.g. of paper, for stiffness, and a number of lamination layerscovering both sides of the base layer.

Preferably, the lamination layers comprise one layer of oxygen-barriermaterial, e.g. an aluminum foil, and a number of layers of heat-sealplastic material covering both sides of the base layer and both sides ofthe layer of oxygen-barrier material. In other words, by proceeding fromthe side eventually forming the inside of package 1, packaging material2 comprises one layer of heat-seal plastic material, one layer ofoxygen-barrier material, another layer of heat-seal plastic material,the base layer, and one or more additional layers of heat-seal plasticmaterial.

The letter M in FIG. 6 indicates a basic unit of packaging material 2,by which to produce package 1, and which may be a precut blank, or aportion of a web of packaging material comprising a succession of basicunits M.

In the first case, basic unit M is folded on a known forming spindle(not shown), is filled with the food product, and is sealed at the topto form the final package.

In the second case, described therein with reference to FIGS. 1 to 12,the web of packaging material 2, comprising a succession of basic unitsM, is:

-   -   folded into a cylinder and sealed longitudinally to form a        vertical tube;    -   filled continuously with the food product; and    -   sealed transversely and cut into basic units M, which are then        folded to form respective packages 1.

After completion of these operations, package 1 has:

-   -   a bottom transverse sealing band 18 (FIG. 5) crossing bottom        panel 10 along a centre line thereof and extending parallel to        front bottom edge 8 a and rear bottom edge 8 b;    -   a top transverse sealing band 19 (FIGS. 1 to 4) crossing top        panel 14 parallel to, and between, front top edge 9 a and rear        top edge 9 b; and    -   a longitudinal sealing band 20 extending perpendicularly between        the bottom transverse sealing band 18 and the top transverse        sealing band 19 along respective portions of bottom panel 10 and        top panel 14 and along the side wall portion 6 defining the rear        face of package 1.

More specifically, after package 1 is completely sealed and formed,bottom panel 10 is crossed by bottom transverse sealing band 18 and byan end portion 20 a of longitudinal sealing band 20 extendingperpendicularly from the bottom transverse sealing band 18.

In a completely analogous way, after package 1 is completely sealed andformed, top panel 14 is crossed by top transverse sealing band 19 and byan end portion 20 b of longitudinal sealing band 20 extendingperpendicularly from the top transverse sealing band 19 and opposite toend portion 20 a; in greater detail, top transverse sealing band 19divides top panel 14 into two zones 14 a, 14 b and end portion 20 b oflongitudinal sealing band 20 extends on one (14 b) of such zones 14 a,14 b from an intermediate portion of the top transverse sealing band 19.

During the forming operations to obtain package 1, top transversesealing band 19 is folded on zone 14 b and end portion 20 b oflongitudinal sealing band 20; in this way, zone 14 a has a bigger areathan zone 14 b and is therefore more suitable for receiving removableportion 17 and opening device 16.

In the example shown in FIG. 6, removable portion 17 has a circularprofile and is designed to be at least partly detached in use from therest of the packaging material by opening device 16 to free a pouropening through which to pour out the product.

Removable portion 17 is formed on packaging material 2 prior to foldingand sealing the packaging material 2 itself to form the finishedpackage.

In the present case, removable portion 17 comprises a so-called“prelaminated” hole, i.e. a circular hole formed through the base layeronly of packaging material 2 and covered, when the packaging material 2itself is laminated, with the layers of heat-seal plastic material andoxygen-barrier material, which adhere to one another at the hole.

With particular reference to FIG. 6, basic unit M of packaging material2 has a rectangular configuration and is delimited by:

-   -   two side boundary edges 22 parallel to a longitudinal direction        coinciding with longitudinal direction A in an upright condition        of basic unit M;    -   a bottom boundary edge 23 parallel to a transversal direction B        orthogonal to longitudinal direction A; and    -   a top boundary edge 24 parallel to transversal direction B and        to bottom boundary edge 23.

Basic unit M of packaging material 2 comprises a number of crease linesdefining respective fold lines, along which the packaging material 2itself is folded to form the finished package 1.

More specifically, basic unit M comprises two transversal crease lines25, 26 extending transversally with respect to longitudinal direction Aand dividing the basic unit M itself into:

-   -   a bottom region 27 containing a bottom crease pattern 28 and        configured to form bottom portion 3 of package 1;    -   a top region 29 containing a top crease pattern 30 and        configured to form top portion 4 of package 1; and    -   an intermediate region 31 contained between transversal crease        lines 25, 26, interposed between bottom region 27 and top region        29 and designed to form side wall portions 6 of package 1.

Transversal crease line 25 extends parallel to bottom boundary edge 23and top boundary edge 24 and is arranged closer to bottom boundary edge23 than transversal crease line 26. Transversal crease line 25 isconfigured to define bottom peripheral outline 8 of package 1.

In particular, transversal crease line 25 includes:

-   -   a bottom central portion 25 a configured to define bottom front        edge 8 a of package 1;    -   two bottom end portions 25 b arranged on opposite sides of        bottom central portion 25 a, located adjacent to respective side        boundary edges 22 and configured to define bottom rear edge 8 b        of package 1; and    -   two bottom side portions 25 c, extending adjacent to opposite        sides of bottom central portion 25 a, connecting the central        portion 25 a itself to the respective end portions 25 b and        designed to define respective bottom side edges 8 c of package        1.

Transversal crease line 26 is arranged closer to top boundary edge 24than transversal crease line 25 and is configured to define topperipheral outline 9 of package 1. In particular, transversal creaseline 26 has a broken-line shape with:

-   -   a top central portion 26 a parallel to transversal direction B        and configured to define top front edge 9 a of package 1;    -   two top end portions 26 b parallel to transversal direction B,        arranged closer to top boundary edge 24 than top central portion        26 a and configured to define top rear edge 9 b of package 1;        and    -   two inclined top side portions 26 c, having slanted        configurations with respect to longitudinal direction A and        transversal direction B and each one connecting top central        portion 26 a to respective top end portions 26 b.

As visible in FIG. 6, top side portions 26 c converge towards topcentral portion 26 a.

Basic unit M includes two further transversal crease lines 32, 33extending parallel to direction B and placed near bottom boundary edge23 and top boundary edge 24, respectively; transversal crease lines 32,33 delimit with bottom boundary edge 23 and top boundary edge 24respective bottom transversal sealing area 34 and top transversalsealing area 35 configured to define bottom transversal sealing band 18and top transversal sealing band 19 of package 1.

Bottom crease pattern 28 is designed to produce bottom panel 10 andbottom lateral flaps 11 of package 1. In particular, bottom creasepattern 28 includes, in a known manner, four longitudinal crease lines36 a, 36 b parallel to longitudinal direction A and extending betweentransversal crease lines 25 and 32.

Longitudinal crease lines 36 b are the most internal ones, whilstlongitudinal crease lines 36 a are located near opposite side boundaryedges 22; the area between longitudinal crease lines 36 b as well as theareas delimited by longitudinal crease lines 36 a with the respectiveside boundary edges 22 are configured to define bottom panel 10 ofpackage 1.

In each of the areas delimited between longitudinal crease lines 36 aand 36 b, bottom crease pattern 28 further includes two additionalcrease lines 37, 38 inclined with respect to both longitudinal directionA and transversal direction B.

In particular, the additional crease lines 37, 38 of each pair have oneend in common located on transversal crease line 32 and opposite endslocated at the intersection points between transversal crease line andlongitudinal crease lines 36 a and 36 b, respectively. In this way, eachpair of additional crease lines 37, 38 delimits a triangle 39 with thesegment of transversal crease line 25 comprised between the additionalcrease lines 37, 38 themselves.

Each area between longitudinal crease lines 36 a and 36 b is configuredto define one respective bottom lateral flap 11 of package 1.

Top crease pattern 30 is designed to produce top panel 14 and toplateral flaps 15 of package 1. In particular, top crease pattern 30includes four longitudinal crease lines 40 a, 40 b parallel tolongitudinal direction A and extending between transversal crease lines26 and 33.

Longitudinal crease lines 40 b are the most internal ones, whilstlongitudinal crease lines 40 a are located near opposite side boundaryedges 22; the area between longitudinal crease lines 40 b as well as theareas delimited by longitudinal crease lines 40 a with the respectiveside boundary edges 22 are configured to define top panel 14 of package1. Removable portion 17 is formed in the area of top region 29 comprisedbetween longitudinal crease lines 40 b.

In each of the areas delimited between longitudinal crease lines 40 aand 40 b, top crease pattern 30 further includes two additional creaselines 41, 42 inclined with respect to both longitudinal direction A andtransversal direction B.

In particular, the additional crease lines 41, 42 of each pair have oneend in common located on transversal crease line 33 and opposite endslocated at, or adjacent to, the opposite ends of the respective inclinedtop side portion 26 c of transversal crease line 26.

In this way, each pair of additional crease lines 41, 42 delimits atriangle 43 with the respective top side portion 26 c of transversalcreased line 26.

Each area between longitudinal crease lines 40 a and 40 b is configuredto define one respective top lateral flap 15 of package 1.

According to an important aspect of the present invention, the length oftop central portion 26 a of transversal crease line 26 is different fromthe length of bottom central portion 25 a of transversal crease line 25;in addition, the length of each of bottom side portions 25 c oftransversal crease line 25 is also different from the length of theprojection R, parallel to longitudinal direction A, of each of top sideportions 26 c of transversal crease line 26 on a reference line Sparallel to transversal crease line 25 and containing top centralportion 26 a.

In particular, the length of top central portion 26 a is smaller thanthe length of bottom central portion 25 a; in a different manner, thelength of each projection R is greater than the length of thecorresponding bottom side portion 25 c.

As visible in FIG. 6, the length of bottom central portion 25 acorresponds to the length of the segment of transversal crease line 32comprised between longitudinal crease lines 36 b; in a completelyanalogous manner, the length of top central portion 26 a corresponds tothe length of the segment of transversal crease line 33 comprisedbetween longitudinal crease lines 40 b.

The same applies to bottom side portions 25 c, whose lengths correspondto the lengths of the respective segments of transversal crease line 32comprised between each pair of longitudinal crease lines 36 a and 36 b.Analogously, the lengths of projections R correspond to the lengths ofthe respective segments of transversal crease line 33 comprised betweeneach pair of longitudinal crease lines 40 a and 40 b.

It is important to note that the length of top front segment Q1 and toprear segment Q2 of top quadrilateral Q corresponds to the length of topcentral portion 26 a; in an analogous manner, the length of top sidesegments Q3 of top quadrilateral Q corresponds to the length ofprojections R.

In the embodiment shown in FIG. 6, intermediate region 31 includes acentral transversal band 44 having a uniform structure, i.e. lacking anycreasing or weakening, and crossing the areas of the intermediate region31 itself designed to form the respective lateral edge zones 7 of sidewall portions 6 of package 1.

Preferably, intermediate region 31 of basic unit M further comprises aplurality of V-shaped crease lines 45 having respective vertices 46located on or adjacent to the transversal crease lines 25, 26 and atgiven points thereof designed to define the opposite ends of respectivelateral edge zones 7 delimiting the side wall portions 6 of package 1;each V-shaped crease line 45 extends from and in proximity of therespective transversal crease line 25, 26 up to central transversal band44 and comprises two legs 47 diverging from the respective vertex 46.

In particular, each V-shaped crease line 45 extends from the respectivetransversal crease line 25, 26 towards the other transversal crease line26, 25 and has a size, parallel to longitudinal direction A, greaterthan zero and smaller than one fourth, preferably smaller than onetenth, of the total height of intermediate region 31 measured parallelto the longitudinal direction A itself.

It is pointed out that, in the present description and in the claims,the term “total height of intermediate region 31” corresponds to thetotal height of the package.

In practice, each V-shaped crease line 45 extending from transversalcrease line 25 and the corresponding V-shaped crease line 45 extendingfrom transversal crease line 26 are spaced apart parallel tolongitudinal direction A.

Preferably, each V-shaped crease line 45 has a size, parallel tolongitudinal direction A, smaller than the maximum height of bottomregion 27 or top region 29 measured parallel to the longitudinaldirection A itself.

More preferably, each leg of the V-shaped crease lines 45 has a lengthsmaller than the maximum length of the heights of triangles 39, 43 withreference to their bases on respective transversal crease lines 25, 26.

In the example shown, each V-shaped crease line 45 has a size, parallelto longitudinal direction A, substantially equal to one fourteenth ofthe total height of intermediate region 31 measured parallel to thelongitudinal direction A itself.

As visible in FIGS. 1 to 4, V-shaped crease lines are the only creaselines present in intermediate region 31 at the areas designed to definelateral edge zones 7 between side wall portions 6 of package 1.

Due to the absence of continuous longitudinal crease lines betweentransversal crease lines 25, 26, the resulting package 1 presents around configuration along lateral edge zones 7. V-shaped crease lines 45perform the function of easing folding of the packaging material 2 atthe corners between lateral edge zones 7 of side wall portions 6 andbottom peripheral outline 8 and top peripheral outline 9 withoutaffecting the round configuration of lateral edge zones 7.

In the example shown, legs 47 of each V-shaped crease line 45 arerectilinear or straight; as a possible alternative not shown, legs 47 ofeach V-shaped crease line 45 may also be curved, preferably with theirconcavities facing one another.

Preferably, legs 47 of each V-shaped crease line 45 delimit an anglecomprised between 45° and 90°.

Number 1′ in FIG. 7 indicates as a whole a different embodiment of asealed package according to the present invention and obtained by abasic unit M′ (FIG. 8) of sheet packaging material 2. Package 1′ beingsimilar to package 1, the following description is limited to thedifferences between them, and using the same references, where possible,for identical or corresponding parts; the same applies for basic unitsM′ and M.

In particular, package 1′ differs from package 1 only in that lateraledge zones 7 between side wall portions 6 are defined by respectivelongitudinal crease lines 50 extending between transversal crease lines25 and 26. Longitudinal crease lines 50 are slightly slanted withrespect to longitudinal direction A due to the different lengths betweenbottom central portion 25 a and top central portions 26 a of transversalcrease lines 25, 26 as well as between bottom side portions 25 c oftransversal crease line 25 and respective projections R on referenceline S.

In this case, there is no need for V-shaped crease lines, which aretherefore absent.

Number 1″ in FIG. 9 indicates as a whole a different embodiment of asealed package according to the present invention and obtained by abasic unit M″ (FIG. 10) of sheet packaging material 2. Package 1″ beingsimilar to package 1, the following description is limited to thedifferences between them, and using the same references, where possible,for identical or corresponding parts; the same applies for basic unitsM″ and M.

In particular, package 1″ differs from package 1 only by having a toppanel 14″ that extends horizontally and parallel to bottom panel 10.

In greater details, top panel 14″ is delimited by a top peripheraloutline 9″ (formed by edges 9 a″, 9 b″, 9 c″) parallel to bottomperipheral outline 8 and deriving by a transversal crease line 26″ alsoparallel to transversal crease line 25 and to transversal direction B.

In this case, top panel 14″ extends entirely on reference plane P andtherefore the projection of top panel 14″ on this latter plane, i.e. topquadrilateral Q, coincides with the top panel 14″ itself.

The same applies to the projections R of top side portions 26 c″ oftransversal crease line 26″ on reference line S, which coincide with thetop side portions 26 c″ themselves; in fact, in this case, referenceline S coincides with top transversal crease line 26″.

Number 1″′ in FIG. 11 indicates as a whole a different embodiment of asealed package according to the present invention and obtained by abasic unit M″′ (FIG. 12) of sheet packaging material 2. Package 1″′being similar to package 1″, the following description is limited to thedifferences between them, and using the same references, where possible,for identical or corresponding parts; the same applies for basic unitsM″′ and M″.

In particular, package 1″′ differs from package 1″ only in that lateraledge zones 7 between side wall portions 6 are defined by respectivelongitudinal crease lines 50 extending between transversal crease lines25 and 26. Even in this case, longitudinal crease lines 50 are slightlyslanted with respect to longitudinal direction A due to the differentlengths between bottom central portion 25 a and top central portion 26a″ of transversal crease lines 25, 26″ as well as between bottom sideportions 25 c and top side portion 26 c″ of the same transversal creaselines 25, 26″.

Thanks to the presence of longitudinal crease lines 50, there is no needfor V-shaped crease lines, which are therefore absent.

The advantages of packages 1, 1′, 1″, 1″′ and basic units M, M′, M″, M″′of packaging material 2 according to the present invention will be clearfrom the above description.

In particular, all the solutions of packages 1, 1′, 1″, 1″′ describedpresent bottom portions 3 slightly different from the top portions 4. Inthis way, it is possible to optimize filling of the transport palletswith the finished packages 1, 1′, 1″, 1″′, which present highflexibility in their dimensions without imparting relevant changes intheir appearance. For instance, a slimmer bottom portion 3 than the topportion 4 permits to compensate the bulging effect produced by gravityon the pourable product contained in the package when placed in theupright position, which product tends to accumulate in the bottomportion of the package 1, 1′, 1″, 1″′, 1″″ itself.

Clearly, changes may be made to packages 1, 1′, 1″, 1″′ and basic unitsM, m′, M″, M″′ of packaging material 2 as described and illustratedherein without, however, departing from the scope of protection definedin the accompanying claims.

1. A sealed package containing a pourable food product and comprising abottom portion, a top portion and a main portion interposed between saidbottom portion and said top portion and including a plurality of sidewall portions; wherein said main portion is divided from said bottomportion and said top portion respectively by a bottom peripheral outlineand a top peripheral outline, each having an endless configuration andextending transversally with respect to a longitudinal direction, alongwhich the total height of the package is defined; wherein each of saidbottom peripheral outline and said top peripheral outline has abroken-line shape and is formed by a plurality of contour edges joinedto each other; wherein said bottom portion comprises a quadrilateralbottom panel delimited by said bottom peripheral outline and extendingorthogonal to said longitudinal direction; and wherein said top portioncomprises a quadrilateral top panel delimited by said top peripheraloutline and extending transversally to said longitudinal direction-;wherein the area of the bottom panel is different from the area of a topquadrilateral obtained by projecting, along said longitudinal direction,said top panel on a reference plane parallel to said bottom panel,crossing the package and containing at least one of the contour edges ofsaid top peripheral outline.
 2. The package as claimed in claim 1,wherein said reference plane contains at least a top front edge of thecontour edges of said top peripheral outline.
 3. The package as claimedin claim 1, wherein the area of said bottom panel is smaller than thearea of said top quadrilateral.
 4. The package as claimed in claim 1,wherein said contour edges of said bottom peripheral outline include abottom front edge, a bottom rear edge and two bottom side edges andwherein said top quadrilateral includes a top front segment,corresponding to said bottom front edge, a top rear segment,corresponding to said bottom rear edge, and two top side segments,respectively corresponding to said bottom side edges.
 5. The package asclaimed in claim 4, wherein said bottom side edges have the same lengthand said top side segments have the same length; and wherein the lengthof said bottom side edges is different from the length of said top sidesegments.
 6. The package as claimed in claim 5, wherein said length ofsaid bottom side edges is smaller than said length of said top sidesegments.
 7. The package as claimed in claim 4, wherein said bottomfront edge and said bottom rear edge have the same length and said topfront segment and said top rear segment have the same length; andwherein the length of said bottom front edge and said bottom rear edgeis different from the length of said top front segment and said top rearsegment.
 8. The package as claimed in claim 7, wherein said length ofsaid bottom front edge and said bottom rear edge is greater than saidlength of said top front segment and said top rear segment.
 9. Thepackage as claimed in claim 1, wherein said top panel is slanted withrespect to said bottom panel, said reference plane and said longitudinaldirection.
 10. The package as claimed in claim 1, wherein said top panelis parallel to said bottom panel and wherein said top quadrilateralcoincides with said top panel.
 11. The package as claimed in claim 1,wherein each of said side wall portions is delimited by two roundedlateral edge zones convex outward.
 12. The package as claimed in claim1, wherein each of said side wall portions is delimited by two straightlateral edge zones.
 13. A sheet packaging material for producing asealed package containing a pourable food product, said packagingmaterial having a rectangular or square configuration with two boundaryedges parallel to a longitudinal direction and two other boundary edgesparallel to a transversal direction orthogonal to said longitudinaldirection; said packaging material comprising at least a bottomtransversal crease line and a top transversal crease line extendingtransversally to said longitudinal direction and dividing the packagingmaterial into: a bottom region containing a bottom crease pattern andconfigured to form a bottom portion of said package; a top regioncontaining a top crease pattern and configured to form a top portion ofsaid package; and an intermediate region contained between said bottomtransversal crease line and said top transversal crease line, interposedbetween said bottom region and said top region and designed to form amain portion of said package having a plurality of side wall portions;wherein said bottom transversal crease line and said top transversalcrease line are configured to define a bottom peripheral outline and atop peripheral outline of said package respectively dividing said bottomportion and said top portion from said main portion; wherein said bottomtransversal crease line extends parallel to said transversal directionand includes a bottom central portion, designed to define a bottom frontedge of said package, and two bottom side portions. extending onopposite sides of said bottom central portion and designed to definerespective bottom side edges of said package; wherein said toptransversal crease line includes a top central portion, designed todefine a top front edge of said package, and two top side portions,extending on opposite sides of said top central portion and designed todefine respective top side edges of said package; wherein said bottomcrease pattern is configured to define a quadrilateral bottom panel ofsaid package and said top crease pattern is configured to define aquadrilateral top panel of said package; wherein the length of said topcentral portion of said top transversal crease line is different fromthe length of said bottom central portion of said bottom transversalcrease line.
 14. The packaging material as claimed in claim 13, whereinthe length of each of said bottom side portions of said bottomtransversal crease line is different from the length of the projection,parallel to said longitudinal direction, of each of said top sideportions of said top transversal crease line on a reference lineparallel to said bottom transversal crease line and containing at leastsaid top central portion.
 15. The packaging material as claimed in claim14, wherein said length of each of said bottom side portions is smallerthan said length of the corresponding said projection.
 16. The packagingmaterial as claimed in claim 13, wherein said length of said bottomcentral portion of said bottom transversal crease line is greater thansaid length of said top central portion of said top transversal creaseline.
 17. The packaging material as claimed in claim 13, wherein saidtop side portions of said top transversal crease line are inclined withrespect to both said longitudinal direction and said transversaldirection and converge towards said top central portion.
 18. Thepackaging material as claimed in claim 13, wherein said top transversalcrease line is parallel to said bottom transversal crease line andcoincides with said reference line, and wherein said projections of saidtop side portions on said reference line coincide with said top sideportions.
 19. The packaging material as claimed in claim 13, furthercomprising a plurality of longitudinal crease lines extending betweensaid bottom transversal crease line and said top transversal crease lineand configured to define respective lateral edge zones of the side wallportions of said package.
 20. The packaging material as claimed in claim19, wherein said longitudinal crease lines are slightly slanted withrespect to said longitudinal direction.